Magnetic heat exchanging unit for magnetic refrigerator

ABSTRACT

A magnetic refrigerator includes a magnetic heat exchange unit including a magnet.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/KR2006/004671, filed on Nov. 9, 2006, entitled “MagneticHeat-Exchanging Unit for Magnetic Refrigerator,” which claims priorityunder 35 U.S.C. §119 to Application No. KR 10-2005-0107307 filed on Nov.10, 2005, the entire contents of which are hereby incorporated byreference.

FIELD OF THE INVENTION

The present invention relates to a magnetic heat exchange unit for amagnetic refrigerator including a magnet.

BACKGROUND

A conventional magnetic refrigerator is disclosed in U.S. Pat. No.6,668,560. As shown in FIGS. 1 and 2, in accordance with theconventional magnetic refrigerator, while a heat transfer fluid 17entering into a cold side inlet port 22 through a cold side inlet portpipe 21 flows to a hot side outlet port 34, the heat transfer fluid 17absorbs a heat generated by a magnetocaloric effect of a magnetocaloricmaterial 12 having a magnetic field applied thereto and exits to a hotside outlet port pipe 33 through a hot side outlet port ports 34 to coolthe magnetocaloric material 12. A hot side sequentially passes the hotside outlet port pipe 33, a valve 71, a pump 60, and a hot heatexchanger 62 and flows into a magnetic heat exchange compartment 13. Ina hot side inlet port pipe 31, the hot side is divided into the hot sideinlet port pipe 31 and a cold side outlet port 23, and meets a cold sideat a cold side outlet port pipe 24 and proceed to a valve 74. When thehot side moves from a hot side inlet port 32 to the cold side outletport pipe 24, the hot side is cooled by passing the magnetocaloricmaterial 12 already cooled by the hot side. The cold side that haspassed through the valve 74 passes a cold heat exchanger 63 and flows topipes 83 and 21 to repeat a cycle (a detailed description is omitted.See U.S. Pat. No. 6,668,560 for omitted reference numerals).

However, the conventional magnetic heat exchange unit 13 comprises amagnetic heat exchange compartment including a container containing themagnetocaloric material passing a flow of the heat transfer fluid.

When the heat transfer fluid enters through an inlet mesh, passesthrough the heat transfer fluid and exits via a outlet mesh, aseparation of the heat transfer fluid in a form of a powder and the heattransfer fluid is established by the outlet mesh, thereby the heattransfer fluid is lost.

Moreover, the heat transfer fluid is accumulated at the outlet meshwhich the exit of the heat transfer fluid according to an intensity of aflow of the heat transfer fluid to block the flow of the heat transferfluid.

SUMMARY

It is an object of the present invention to provide a magnetic heatexchange unit for a magnetic refrigerator that prevents a loss of a heattransfer fluid and that allows the heat transfer fluid to flow smoothly.

In order to achieve the above-described object, there is provided amagnetic heat exchange unit, comprising: a container including an inletport, an outlet port and a magnetic heat exchange chamber; amagnetocaloric material contained in the magnetic heat exchange chamber,the magnetocaloric material exchanging heat by allowing a flow of a heattransfer fluid to pass through; and a magnet for applying an attractiveforce to the magnetocaloric material.

In accordance with the magnetic heat exchange unit, the loss of themagnetocaloric material is suppressed by holding the magnetocaloricmaterial with the magnet, thereby allowing the heat transfer fluid toflow smoothly.

The magnet may be attached to the container or may be disposed in themagnetocaloric material.

The magnetic heat exchange unit in accordance with the present inventionmay further comprise a mesh disposed at the inlet port and the outletport, respectively to further prevent the loss of the magnetocaloricmaterial.

In addition, it is preferable that the magnetocaloric material comprisesa gadolinium.

According to present invention, a magnetic heat exchange unit for amagnetic refrigerator that prevents a loss of a heat transfer fluid andthat allows the heat transfer fluid to flow smoothly can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view illustrating a heat transfer fluid in aconventional rotational magnet magnetic refrigerator.

FIG. 2 is a plan view exemplifying a magnetic heat exchange unitincluding a magnetocaloric material of FIG. 1.

FIGS. 3 and 4 are a plan view and a lateral view respectivelyexemplifying a magnetic heat exchange unit including a magnetocaloricmaterial in accordance with a preferred embodiment of the presentinvention.

DETAILED DESCRIPTION

The above-described objects and other objects and characteristics andadvantages of the present invention will now be described in detail withreference to the accompanied drawings.

FIGS. 3 and 4 are a plan view and a lateral view respectivelyexemplifying a magnetic heat exchange unit including a magnetocaloricmaterial in accordance with a preferred embodiment of the presentinvention.

As shown in FIGS. 3 and 4, the magnetic heat exchange unit 213 comprisesa container, a magnetocaloric material contained in the container and amagnet 14 for applying an attractive force to the magnetocaloricmaterial.

A magnetic heat exchange compartment containing the magnetocaloricmaterial, and an inlet port and an outlet port for passing a flow of theheat transfer fluid are formed in the container. A pipe is connected tothe inlet port and the outlet port.

It is preferable that the inlet port 16 and the outlet port 17 arearranged on a plane as shown in FIG. 4 in order to prevent the loss ofthe heat transfer fluid and to allow the heat transfer fluid to flowsmoothly.

The magnetocaloric material has a characteristic wherein a temperaturethereof is varied when a magnetic field is applied. A material havingsuch characteristic includes a gadolinium (Gd) of a fine powder type.The gadolinium has pores having a high osmosis to the flow of the heattransfer fluid, and a superior absorption and emission of a heat. It ispreferable that the magnet 14 is attached to the container or disposedin the magnetocaloric material.

As shown in FIGS. 3 and 4, when the magnet is attached to the container,the magnet is attached on an outer wall (or an inner wall) of thecontainer to attract the magnetocaloric material.

The magnet 14 causes the magnetocaloric material to lump together sothat the loss by the flow of the heat transfer fluid is prevented.

In addition, the accumulation of the magnetocaloric material at theoutlet port 17 is minimized to allow the heat transfer fluid to flowsmoothly.

Particularly, the inlet mesh and the outlet mesh are installed at theinlet port and the outlet port, the loss of the magnetocaloric materialis suppressed even more.

While the present invention has been particularly shown and describedwith reference to the preferred embodiment thereof, it will beunderstood by those skilled in the art that various changes in form anddetails may be effected therein without departing from the spirit andscope of the invention as defined by the appended claims

As described above, the magnetic heat exchange unit in accordance withthe present invention provides following advantages.

The loss of the magnetocaloric material is suppressed by holding themagnetocaloric material with the magnet, and the magnetocaloric materialthe heat transfer fluid may be easily separated, thereby preventing theblocking of the outlet port and allowing the heat transfer fluid to flowsmoothly.

In addition, when the meshes are installed at the inlet port and theoutlet port, the loss of the magnetocaloric material is minimized by afiltering even when the magnetocaloric material is lost.

1. A magnetic heat exchange unit, comprising: a container including aninlet port, an outlet port and a magnetic heat exchange chamber; amagnetocaloric material contained in the magnetic heat exchange chamber,the magnetocaloric material exchanging heat by allowing a flow of a heattransfer fluid to pass through; and a magnet for applying an attractiveforce to the magnetocaloric material.
 2. The magnetic heat exchange unitin accordance with claim 1, wherein the magnet is attached to thecontainer.
 3. The magnetic heat exchange unit in accordance with claim1, wherein the magnet is disposed in the magnetocaloric material.
 4. Themagnetic heat exchange unit in accordance with claim 1, furthercomprising a mesh disposed at the inlet port and the outlet port,respectively.
 5. The magnetic heat exchange unit in accordance withclaim 4, wherein the magnetocaloric material comprises gadolinium.